Keith Moore writes:
seems reasonable at least from a theoretical perspective. from a
practical perspective, I wonder if it's at all realistic to request
that email not be archived, or that some part of a message not be
A good question, but I think it's beside the point. If the existing
non-standard field is reasonably widely used, both by message writers
and archivers, isn't that in itself reason enough to standadize it?
To answer your question, no. Just because a field is widely used does
not mean that it meets the criteria for standardization.